Manipulating morphology and surface engineering of spinel cobalt oxides to attain high catalytic performance for propane oxidation

The selective synthesis of nanomaterials with different morphologies and crystal facets is of great signif-icance for catalytic properties and practical applications. We report a strategy for controllable fabrication of hierarchical Co3O4 materials with various morphologies (ellipsoidal, flowerlike, book-shaped, spindle-like) and study their catalytic properties in propane oxidation. Co3O4-B (book-shaped) is found to exhibit the highest propane oxidation rate (0.86 x 10(-8) mol m(-2) s(-1)) and the highest turnover frequency (TOF = 11.49 x 10(-3) s(-1)) at 220 degrees C. This confirms that Co3O4-B provides a higher specific surface area, a highly exposed {110} facet, and abundant Co3+ cations, which make it exhibit favorable low-temperature reducibility and oxygen mobility and thus improve its catalytic activity. In situ diffuse reflectance infra-red Fourier transform spectroscopic analysis reveals that the intermediates, such as carboxylate and car-bonate species, are involved in propane oxidation. Furthermore, Co3O4-B shows high water-resistance performance, and no significant deactivation is observed after long-term stability and reusability tests. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

The controllable fabrication of hierarchical Co3O4 materials with various morphologies was reported in this study. Among them, the book-shaped Co3O4-B exhibited the highest catalytic activity in propane oxidation, showing promising potential for practical applications.